Method of softening shoe stiffeners



Oct. 29, 1929.

F. w. EAGER IETHOD OF SOFTENING SHOE STIFFENERS 'Filed June 1, 1927 Ell/il/l/fll Ill/l I! III I f .Il'llllllllll I Patented Oct. 29, 1929 1 UNITED STATES.

PATENT OFFICE FREDERICK w. EAGEE, or QUmoY, MASSACHUSETTS, AssrGNon 'ro HARRY 1a. .BECK I WITH, or BEOQKLINE; MASSACHUSETTS, a

M THOD, 0 SOFTENING SHOE: sTIEF EEs I nppl ication filed June 1, 1927; Serial no.,'195,sos.

It is now common practice to incorporate stiffening members in shoes, such stiffening members containing thermoplastic material which may be softened when subjectedto moderate heat so that the stifieners may be made sufliciently limp to permit them to be shaped to the lasts during the manufacture of the shoes. In order to soften the stifli'eners inthis manner, it has been'eustomary to in sert-the shoe portion containing the stiffener in a heater in which the shoe upper material at least is subjected to moist heat. This method has been satisfactory in most cases for the heavier grades of leather, but has been unsatisfactory when the shoe uppers have been composed of delicate or highly colored or embossed leather, the more highly colored leather tending to be more or less bleached, the delicate or light coloredto be stained, and the embossing of embossed leathermade less pronounced by this treatment. Where the upper has cutouts or perforations therethrough this method has not been entirely satisfactory, particularly where the usual cabarettas are used as lining material-as this material is shrunk and turned'dark thereby.

Sometimes colored surfaces for leather are produced by applying successive coatings of different colors, the underlying colors imparting a modification to the surface colors of the completed products. When such leather is subjected to the moist hot vapor treatment as heretofore practiced, underlying colors are brought to the surface more decidedly so that a staining effect results.

I have concluded as the result of much experience that the moist heat of itself does not cause this damage to the leather, but that it is due to the fact that when shoes are placed therein they are relatively cold, this causing an initial condensation of moisture which, as the shoe parts are raised in temperature to substantially that of the vapor, is re-evaporated. I believe that it is this free moisture absorbed by the shoe material prior to the shoe reaching substantially the temperature of the moist vapor that does the damage.

According to the present invention, therefore, this condensation of moisture on the upper material is prevented. A method which I have found most effective for the purpose is to cover the shoe part which is to be nserted in the heater with a dry fabric on which the initial condensation is deposited,

the fabric being of suflicient weight to prevent the moisture from striking through onto the shoe during the time necessary to raise the shoe and fabric to a temperature sufiiciently high to cause re-evaporization of the condensate. softened the fabric may conveniently be formed into a bag having an open end which may be drawn over the toe of the shoe to be treated prior to its insertion into the toe heater. Fabricwhich has been found quite suitable for the purpose is '7 ounce cotton duck/ When made into a bag and drawn over the toe portion of the shoe it notonly protects the upper, but it also protects the sole or insole from the moisture. Heretofore. shoe heaters have commonly been made with means for supplying dry heat to contact with the innersole, it having been found that the moist heat is likely to damage the innersole. By protecting theinnersole from the initial condensation, as bymeans of the fabric, the

need for dry heat is entirely avoided, so that.

less complicated heating mechanism may b entirely satisfactory. a

For a more complete understanding of this invention, reference may be had to the accompanying drawings showing the invention as applied to the softening/of toe stifi'enersand in which I Y Figure 1 is 'aperspective of the fabric bag for use in connection with the practice of this invention. 1 I I Figure 2 is a central longitudinal section through the same showing in dotted lines the position of a shoe with relationythereto in condition! for insertion in the heater.

Figure 3 is a vertical section, somewhat diagrammatic, through one form of heater showing the'shoe'toe encased in the bag in position therein for the softening operation. Referring to these drawings,'at 1 is indicated a fabric bag having an open end 2, the bag being so shaped that it maybe drawn over the toe portion of ashoe as shown in Figure 2, the shoe being indicated at dotted lines at 3.

When toe stifi'eners are to be The bag may be made in any suitable manner,

but as shown it is composed of a pair of mat closely and the shoe toe with the; bag there-' on is then thrust into the moist heat in the treating chamber 10 of the heater 11, asshown a wire screen I3 placed therea-bout.

in Figure 3, the bag being-f su-fficient lengthto cover all of the shoe which might otherwise 7 be reached by moisture, from the heater. While any ordinary type of moist heat shoe heater may be used, as shown this, figure,

the moist heatrises through amass of fibrous material 1- 2, inthe baseoi the chamber 10, this l-ll iterial being held in positionby means of Moi-st vapor is supplied tothe interior of the chamber; 10, continuously by: anysuitable means so as to maintain theatmosphere therein at a temperature; snficiently high to soften the thermoplastic material in the toe stifiener; When the shoe toewith the bag thereon, which is at ordinary room temperature, is. inserted into the; chamber 10, the, vapor. impinging thereon is i mediate y con e h c ndensate being-caught by the bag and prevented thereby from. passi g thro gh d reaching the shoe parts Within the bag. The bag and;v shoe r t en brought p to substantiallythe temperature of the, vapor within, the

chamber 10,, whereupon the cond nsate is again. vaporized, the. moisture within the chamber being somewhat less than at the saturation point, and the toe stifiener is softenedwhile the moistirre in the vapor pre 7 vents injury to the upper leather! When the stiiiener has been softened to! thefdes-ired degree the shoe and bag: may be removed, the

bag removed from the. shoe, and the forming operations on the shoe toe completed. The

initial heating of the shoe is thus produced by substantially dry heat, the bag delaying the contact oft-he moisture with the shoe'until such time asthe shoe has been raised to a temperaturesuificiently high so that moisture from the vapor will not be condensed on the 'shoeparts including thermoplastic stifieners,

which comprises covering such parts with a ,dry protecting fabric, and then subjecting said parts to the action of hot vapor for a time sufiicient to soften the stiifeners sufficiently for the shapingoperations. I

2. The method of softening the toe portion of a shoe containing a thermoplastic stiffener,

which comprises drawing a dry fabric bag over said portion and then subjecting said portion while in the bag to moist hot vapor.

- 3. The method of softening the toe portion ofa shoe containing a thermoplastic stiffener,

which comprises heating such portion in moist vapor while the surfaces exposed inthe finished shoe are protected from access by condensation from said vapor. r

4. The method of softening the toe portion of a shoecontai-ninga thermoplastic stifiener which comprises heatil g Such portion in moist; vapor whilecovered; with an dry fabric of substantialweight; ,5, In the process of condi ioning; for shaping: shoe parts including vthermoplastic stifieners by snbjecting them to moist hot Taper, thegmethod of preventing damage, to

such :parts which comprises delaying contact of the moistureof said vapor therewith until said partsbecome heated to such a temperature'that no condensation of vapor thereon occurs on sngch. contact.

j 6;, In the process of conditioning for shaping; shoe p ;art s, including thermoplastic stiifeners by subjecting them toJnioist hot vapor, the m thodei preventing dam ge to such parts, which comprises heating said parts Withrelatively dry heat to such a temperature that moistur from said vapor will not be cendens dth eon and. he 7 subjecting them to suohvapor. a

In testimony whereof I have affixed my signature,v o I ;f

7 FR DER GK EAGER shoe. By this procedure all'the'toeportion, I

and more especiallythe parts exposedin' the finished shoe, such as theouter facerof1 the' upper material is protected from the initial condensation and its color'presei'ved. p

In order that the fabric protective mem ber comprising the bag '1 may properly-perform its function it, islquite essential that it b i l y,' l at lea t so ea y so th t it" eS ot permit free. moisture.tocoineiinto contac withthe shoe,

Having thusadescribed the nature, offthis inventiomit, should be evident to those skilled.

in the art that rvarious changes. and media 'fioa-tions; might be made from the specific method means he ein 'shown Without do:

initially 

